Stormwater, Sewer and Septic Basics

How Does Stormwater Impact Our Water Supply?

A watershed is all the land area that drains into a stream, river, lake or other body of water. Stormwater runoff – rainfall that does not soak into the ground, but instead flows over the land or through storm sewer pipes into these surface waters – is important to replenish our water supply and contributes to maintaining groundwater and surface water flows that support aquatic life and habitat.

Stormwater is not treated at facilities before it enters the environment. Any pollutants or litter picked up by stormwater goes directly into surface water sources.  As the number of impervious surfaces such as rooftops, roads and parking lots increase, the fewer opportunities rainfall has to naturally return to the environment. Proper management of stormwater can help avoid negative environmental impacts like erosion, flooding and contamination of our water.

While stormwater is an important asset for replenishing natural bodies of water, stormwater pollution can make monitoring and treatment of our drinking water more difficult and costly, especially in metropolitan North Georgia where almost all of our drinking water comes from surface water. When managed properly, stormwater can support the health of the aquatic ecosystem of the streams, rivers and lakes that so many use for swimming, fishing or other recreational activities.

How Does Wastewater Pollution Occur?

Wastewater is water that has been used by homes, industry and business that must be treated before it is released back into the environment. Wastewater is either transported by a sewer system to a wastewater treatment plant, or it is treated onsite within a self-contained septic system.

The Metro Water District has 303 wastewater treatment facilities, including 92 publicly owned and 211 privately owned facilities. These facilities clean water that is often contaminated with human waste, oils, soaps and chemicals through a staged process. The steps taken to remove organic matter, contaminants, bacteria and germs are highly regulated to ensure a safe, high-quality water output that can be returned to nature.

Some metro area homes and businesses rely on septic systems in which wastewater is treated onsite. In these cases, water passes into a septic tank, where solid materials settle to the bottom and are broken down by bacteria. Liquids are passed onto a drainfield, where waste materials are broken down by bacteria in the soil. Homeowners should know that maintenance of the system is important for it to properly function. The solids in the septic tank must be pumped periodically—generally every five years is best.